Chillgender is a xenogender in which your gender is chill and lax. This gender usually gives a feeling of comfort
Often this gender is represented with different shades of blue (especially in flags), but can be other colors to identify with ones' alignment.
For instance. Chillgirl is an alligned female with soft shades of pink, but their gender is still very relaxed. Chillboy is the same for chillgirl, just with softer hues of blue.
History
The term was coined on Discord by Yoongi, a headmate of the Yellow Cab Collective. The flags were also made by this individual.